Tiny sponges behave in a counterintuitive way when adsorbing water

(Phys.org)—When a kitchen sponge adsorbs water into its pores, it softens and expands. Now in a new study published in The Journal of Physical Chemistry Letters, scientists have discovered that, when microporous materials adsorb fluid, they initially soften but then stiffen as they adsorb more fluid. It's as if soaking your kitchen sponge in water eventually caused it to harden.